C# LINQ Background Topics

Delegates - Delegate declarations

Why learn about delegates?

When learning LINQ, it is important to have a good understanding of delegates in C#. Many of the more powerful capabilities of LINQ make use of delegates.

What is a delegate?

A delegate is simply a reference to a method. Delegates can be stored and passed around in a variable, and hence they must have a type definition:

private delegate int FuncTwoInts(int one, int two);

The line above defines the type FuncTwoInts. The FuncTwoInts type is a reference to a method that takes two int parameters and returns a single int result.

Exercise

Declare a new type SayHello as a delegate that takes a single string parameter and returns a string result.